“It seems that perfection is reached not when there is nothing left to add, but when there is nothing left to remove.”

Antoine de Saint-Exupéry

Minimalism in all its forms

What is left out of a framework or language is as important as what is included. It’s easy to pile on features, removing them is very hard, and any system will eventually evolve to a point of feature saturation i.e. the point where every new feature added has undesirable interference with existing ones, or the complexity is no longer justified by the functionality it provides. We could describe this state as software senility. Only by putting a lot of efforts and thoughts into how to add as little as possible into Squeryl will it have a healthy longevity.

The functionality that is added should have the smallest conceptual surface area as possible. Lets define the feature density by this ratio : functionality / (conceptual surface area).
The conceptual surface area here means complexity, in terms of API size, number of concepts that need to be introduced. While complexity is certainly a subjective and imprecise concept, extreme bloatware is usually unanimously recognized as such, there is hardly any one for example that could claim that EJB2.0 has a high feature density.

Zero tolerance for redundancy : the worst form of redundancy is the one imposed by a framework or library on user code, followed by redundancy in the DSL.

Keep in mid that a persistence layer addresses only one aspect among many in an application and should leave as much conceptual room as possible for the other aspects.